As antenna technologies have developed from an external antenna to an embedded antenna, small and light antennas have been required.
Since various functions are added to even home appliances as well as the smart phone as the demands for home appliances utilizing a smart phone are increased with the advance of the technology, the small and light antenna has been required. Accordingly, the technology on the small antenna has been continuously performed, and the high-efficiency antenna employing various schemes in a small size has been applied to various wireless appliances.
A radiating element constituting the antenna can be formed with a length corresponding to 4/1 of a wavelength at a resonance frequency in the low frequency band. Compacter antennas for a broad band have been required, and antennas usable in a wider frequency band have been required.